
The Minimum Radiation Visually Perceptible

The Minimum Radiation Visually Perceptible

Potassium Photo-Electric Cells—II
A Study of the Relationship of Illumination and Current

Potassium Photo-Electric Cells—I
A Study of the Relationship of Illumination and Current

Artificial Daylight—I
Light Sources Suitable for Color—Matching

Illumination from Large Area Light Sources—II
Some Experiments Carried Out With Actual Home Conditions

Illumination from Large Area Light Sources—I
Some Experiments Carried Out With Actual Home Conditions

The Distribution of Luminosity in Nature
Great Brightness Below the Horizon is Painfully Felt by the Eye

The Intrinsic Brilliancy of the Glow Worm
Nature Fifty Times as Efficient as Our Best Artificial Light